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Basic Session Initiation Protocol
Published in Radhika Ranjan Roy, Handbook on Session Initiation Protocol, 2018
The Session Initiation Protocol (SIP) is a signaling protocol to set up, modify, and tear down networked multimedia sessions consisting of audio, video, or data applications. The International Engineering Task Force’s (IETF) Request for Comment (RFC) 3261 is the first stable specification that defines SIP in a comprehensive manner. However, RFC 3261 obsoleted the initial SIP RFC 2543 soon after its publication. Eventually, many other RFCs have been published, extending the base capabilities of SIP described in RFC 3261 to meet the requirements of the complexities of net-work-based multimedia session ranging from point-to-point to multipoint calls, including media (audio, video, or data) bridging and feature-rich application sharing in real time. In fact, the enhancements are still going on even today as more sophisticated multimedia-rich requirements are being demanded for standardization for large-scale interoperable implementations.
Prospects for Microsystems Packaging Technology
Published in Yufeng Jin, Zhiping Wang, Jing Chen, Introduction to Microsystem Packaging Technology, 2017
Yufeng Jin, Zhiping Wang, Jing Chen
The main benefits of SIP include (1) low manufacturing cost because of the use of currently available commercial components; (2) short time period required for bringing products into the market; (3) great design and technological flexibility; (4) relative ease of integrating different types of circuits and components. The single integrated module (SLIM) developed by the Georgia Institute of Technology is a typical SIP. This technology increased the efficiency, performance, and reliability of packaging by 10 times, while the size and cost of packaging dropped significantly. By 2010, the wiring density of the technology is expected to reach 6000 cm/cm2, the heat density is expected to reach 100 W/cm2, the component density is expected to reach 5000/cm2, and the I/O density to reach 3000/cm2.
Session Initiation Protocol
Published in Giovanni Bartolomeo, Tatiana Kováčiková, Identification and Management of Distributed Data: NGN, Content-Centric Networks and the Web, 2016
Giovanni Bartolomeo, Tatiana Kováčiková
Following are the four types of logical SIP entities: SIP User Agents (UAs) are the end-user devices, such as cell phones, multimedia handsets, personal PCs, and PDAs, used to create and manage an SIP session. The User Agent Client (UAC) initiates the message. The User Agent Server (UAS) responds to it.SIP registrar servers are databases that contain the location of all UAs within a domain. In SIP messaging, these servers retrieve and send participants’ IP addresses and other pertinent information to the SIP proxy server.SIP proxy servers accept session requests made by an SIP UA and query the SIP registrar server to obtain the recipient UA’s addressing information. They then forward the session invitation directly to the recipient UA if it is located in the same domain or to a proxy server if the UA resides in another domain.SIP redirect servers allow SIP proxy servers to direct SIP session invitations to external domains. SIP redirect servers may reside in the same hardware as SIP registrar severs and SIP proxy servers.
Studying the Impact of SIP Message Differentiation on the Quality of VoIP Session Control Procedures
Published in IETE Technical Review, 2021
Jasmina Baraković Husić, Sabina Baraković, Seudin Kasumović
Voice over Internet Protocol (VoIP) is a technology used to transmit real-time voice over Internet Protocol (IP) based networks. Since its invention, VoIP has the exponential growth becoming an important tool used for business, social, and family communications [1]. The important component of VoIP infrastructure is the session control. It may be achieved through Session Initiation Protocol (SIP). SIP session control infrastructure has to support session setup and teardown procedures for telephony services, process SIP messages carrying Instant Messaging (IM) payload and supporting presence, handle user mobility, and exchange routing information with other session control servers in order to route session setup messages appropriately. Using SIP for these purposes may cause a significant load on the SIP session control infrastructure. Thus, a key requirement for a robust VoIP session control infrastructure is overload control [2].
NomadicBTS: Evolving cellular communication networks with software-defined radio architecture and open-source technologies
Published in Cogent Engineering, 2018
Emmanuel Adetiba, Victor O. Matthews, Samuel N. John, Segun I. Popoola, Abdultaofeek Abayomi
The SDR software back-end comprises of the Soft Base Station Subsystem (SoftBSS) and the Voice over Internet Protocol Private Automatic Branch Exchange (VoIP PABX) software running on a single-board embedded computer or PC with an Operating System (OS). The SoftBSS provides the necessary interconnection between the SDR front-end hardware and the VoIP PABX. SoftBSS implements a software transceiver which performs functions such as frequency tuning, Gaussian Minimum Shift Keying (GMSK) modulation and demodulation, clock synchronization, control command transaction as well as transmission of receive and transmit bursts. It also implements the Session Initiation Protocol (SIP) mapping functions in order to establish SIP connections for processing by the VoIP PABX. For instance, the International Mobile Subscriber Identity (IMSI) stored on the Subscriber Identity Module (SIM) card of a Mobile Station (MS), which is the end-user phone, is presented to the VoIP PABX as an SIP client. The location of the MS is mapped to SIP registration, call connection is mapped to SIP transactions, while Short Message Services (SMS) function is realized through instant messaging extension to SIP (Apvrille, 2011). The SoftBSS, as shown in Figure 1, also contains a Graphical User Interface (GUI) to provide access for configuring the NomadicBTS by technical administrator in a user-friendly manner. As a proof of concept, the SoftBSS was realized, in this present study, using a combination of open-source technologies such as Ubuntu Linux, OpenBTS and GNU Radio (Burgess & Samra, 2008; Reyes et al., 2016).